The present disclosure relates generally to hermetic barrier layers, and more specifically to free-standing multi-laminate hermetic sheets, related structures, and methods of forming hermetic seals.
Hermetic barrier layers can be used to protect sensitive materials from deleterious exposure to a wide variety of liquids and gases. As used herein, “hermetic” refers to a state of being completely or substantially sealed, especially against the escape or entry of water or air, though protection from exposure to other liquids and gases is contemplated.
Approaches to creating hermetic barrier layers include physical vapor deposition (PVD) methods such as sputtering or evaporation, or chemical vapor deposition (CVD) methods such as plasma-enhanced CVD (PECVD) where a hermetic barrier layer can be formed directly on the device or material to be protected. By way of example, both reactive and non-reactive sputtering can be used to form a hermetic barrier layer, for example, under room temperature or elevated temperature processing conditions. Reactive sputtering is performed in conjunction with a reactive gas such as oxygen or nitrogen, which results in the formation of a corresponding compound barrier layer (i.e., oxide or nitride). Non-reactive sputtering can be performed using an oxide or nitride target having a desired composition in order to form a barrier layer having a similar or related composition.
In contrast with non-reactive sputtering, reactive sputtering or CVD can be economically advantageous due to comparatively higher deposition rates. However, although increased throughput can be achieved via reactive sputtering, its inherently reactive nature is generally incompatible with sensitive devices or materials that require protection.
In view of the foregoing, economical and device-compatible hermetic barrier layers that can protect sensitive workpieces such as devices, articles or raw materials from undesired exposure to oxygen, water, heat or other contaminants are highly desirable.
According to one aspect of the current disclosure, a hermetic barrier layer is provided where formation of the barrier layer is decoupled from its application to the workpiece to be protected. Formation of the hermetic barrier layer itself (e.g., via physical or chemical vapor deposition) may involve oxygen, water, solvents, elevated temperatures, ion bombardment, etc. By forming the hermetic barrier layer in a first step, and then applying the hermetic barrier layer to a workpiece in subsequent step, exposure of the workpiece to aggressive or otherwise harmful process conditions during the act of applying the hermetic barrier layer can be avoided.
The disclosure describes a free-standing multi-laminate hermetic barrier that can be configured to at least partially encapsulate a device, article or material that is sensitive to degradation by oxygen, moisture, heat, or other contaminants. A free-standing multi-laminate hermetic sheet comprises one or more inorganic thin films and one or more flexible carrier films alternately configured in a stacked geometry. In particular, a free-standing multi-laminate hermetic sheet according to one embodiment comprises a first carrier film, an inorganic thin film having opposing first and second major surfaces, and a second carrier film, wherein the first major surface of the inorganic thin film is formed over a surface of the first carrier film, and the second carrier film is formed over the second major surface of the inorganic thin film. In further embodiments, a multi-laminate gasket comprises an inorganic thin film formed over a suitable gasket member. The inorganic thin film may comprise one or more oxides or nitrides including various glass compositions, while the carrier films and gasket member can comprise flexible polymeric materials such as polydimethylsiloxane (PDMS), polyethylene-naphthalate (PEN) or polyethylene-terephthalate (PET).
A method of hermetically sealing a workpiece comprises supporting a workpiece on a substrate, forming a multi-laminate hermetic sheet, and encapsulating the workpiece by placing the hermetic sheet over the workpiece and either directly or indirectly in hermetic contact with the substrate in a region of the substrate peripheral to the workpiece.
A device that is initially formed on a surface of a substrate can be hermetically sealed using a multi-laminate sealing assembly that includes a multi-laminate hermetic sheet and a multi-laminate hermetic gasket. The multi-laminate hermetic gasket is disposed on the surface of the substrate peripheral to the device, and the multi-laminate hermetic sheet is disposed over the device and in hermetic contact with the gasket.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the detailed description which follows, the claims, as well as the appended drawings.
It is to be understood that both the foregoing general description and the following detailed description present embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention and together with the description serve to explain the principles and operations of the invention.